package org.apache.maven.project.harness;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.jxpath.ri.QName;
import org.apache.commons.jxpath.ri.compiler.NodeTest;
import org.apache.commons.jxpath.ri.model.NodeIterator;
import org.apache.commons.jxpath.ri.model.NodePointer;
import org.codehaus.plexus.util.xml.Xpp3Dom;

/**
 * A node pointer for JXPath to support <code>Xpp3Dom</code>.
 * 
 * @author Benjamin Bentmann
 */
class Xpp3DomNodePointer extends NodePointer {

  private Xpp3Dom node;

  public Xpp3DomNodePointer(Xpp3Dom node) {
    super(null);
    this.node = node;
  }

  public Xpp3DomNodePointer(NodePointer parent, Xpp3Dom node) {
    super(parent);
    this.node = node;
  }

  @Override
  public int compareChildNodePointers(NodePointer pointer1, NodePointer pointer2) {
    Xpp3Dom node1 = (Xpp3Dom) pointer1.getBaseValue();
    Xpp3Dom node2 = (Xpp3Dom) pointer2.getBaseValue();
    if (node1 == node2) {
      return 0;
    }
    for (int i = 0; i < node.getChildCount(); i++) {
      Xpp3Dom child = node.getChild(i);
      if (child == node1) {
        return -1;
      }
      if (child == node2) {
        return 1;
      }
    }
    return 0;
  }

  @Override
  public Object getValue() {
    return getValue(node);
  }

  private static Object getValue(Xpp3Dom node) {
    if (node.getValue() != null) {
      return node.getValue();
    } else {
      List<Object> children = new ArrayList<Object>();
      for (int i = 0; i < node.getChildCount(); i++) {
        children.add(getValue(node.getChild(i)));
      }
      return children;
    }
  }

  @Override
  public Object getBaseValue() {
    return node;
  }

  @Override
  public Object getImmediateNode() {
    return node;
  }

  @Override
  public int getLength() {
    return 1;
  }

  @Override
  public QName getName() {
    return new QName(null, node.getName());
  }

  @Override
  public boolean isCollection() {
    return false;
  }

  @Override
  public boolean isLeaf() {
    return node.getChildCount() <= 0;
  }

  @Override
  public void setValue(Object value) {
    throw new UnsupportedOperationException();
  }

  @Override
  public NodeIterator childIterator(NodeTest test, boolean reverse, NodePointer startWith) {
    return new Xpp3DomNodeIterator(this, test, reverse, startWith);
  }

  @Override
  public NodeIterator attributeIterator(QName qname) {
    return new Xpp3DomAttributeIterator(this, qname);
  }

}
